Live fire remote units such as Precision Remote's Telepresent Rapid Aiming Platform (TRAP) provide remote control of firearms. Remotely controlled firearms are useful in keeping humans out of hostile environments while defending an area from attack. These units allow an operator to view a target through a video camera and operate the firearm from a remote location.
The firearm is mounted to a base that rotates about a vertical axis. In order to aim the firearm, the base must be able to rotate through yaw control—also known as pan motion. The ideal characteristics for pan motion are: 1) fast slew rotational motion, 2) a wide range of movement up though 360 degrees and 3) extreme accuracy when the pan motion is stopped to properly aim the firearm. This would allow the firearm to be quickly rotated into position and accurately aimed before firing.
These desirable performance characteristics of high speed and high accuracy have been in conflict. When the pan movement is stopped, the yaw control is typically either fast in movement for aiming but inaccurate in positioning or very slow in pan movement and highly accurate in positioning. These operating characteristics previously resulted in some sort of compromise in performance.
In the past high accuracy has been preferable to speed because accuracy of targeting was essential. U.S. Pat. No. 6,237,462, which is hereby incorporated by reference, discloses a linear actuator that is used to accurately control the pan motion of a remotely controlled firearm. This linear actuator provides extremely accurate pan resolution which can be set to be finer than needed by the most accurate rifle application. An example of this high accuracy application can be remotely controlled sniper grade firearms. The linear actuator also provides the subtle but critical qualities of: 1) low hyserisis; 2) low play; 3) self adjusting design so that wear does not degrade performance; and 4) rugged platform able to sustain live fire.
There are some drawbacks to the linear actuator pan control system disclosed in U.S. Pat. No. 6,237,462. The disclosed pan control system has a limited slew range of less than 180 degrees and a maximum speed limited to about 10 degrees per second. Thus, Precision Remote's TRAP mechanism may be vulnerable to enemies located beyond the slew range and may not be able to follow fast moving enemies.
There are other remote control firearm units that slew at a much faster pan speed and further than 180 degrees of rotation, however, these devices typically use rotational positioning actuators which are capable of faster movement but sacrifice positioning accuracy needed to precisely aim the firearm. Although these rotational positioning actuators are faster, they also have greater amounts of inherent “play” than Precision Remote's TRAP mechanism which increases with the age of the unit as the actuator gears begin to wear.
What is needed is a movement platform which provides fast rotational speed and highly accurate positioning.